The present disclosure is broadly concerned with structure for use in supporting and maintaining a patient in a desired position during examination and treatment, including medical procedures such as imaging, surgery and the like. More particularly, it is concerned with structure having patient supports that can be adjusted to allow a surgeon to selectively position the patient for convenient access to the surgical field and provide for manipulation of the patient during surgery including the tilting, angulation or bending of a trunk and/or a joint of a patient while in a generally supine, prone or lateral position. It is also concerned with structure for adjusting and/or maintaining the spatial relation between the inboard ends of the patient supports and for synchronized translation of the upper body of a patient as the inboard ends of the two patient supports are angled upwardly and downwardly.
Current surgical practice incorporates imaging techniques and technologies throughout the course of patient examination, diagnosis and treatment. For example, minimally invasive surgical techniques, such as percutaneous insertion of spinal implants involve small incisions that are guided by continuous or repeated intra-operative imaging. These images can be processed using computer software programs that product three dimensional images for reference by the surgeon during the course of the procedure. The patient support system should be constructed to permit unobstructed movement of the imaging equipment and other surgical equipment around, over and under the patient throughout the course of the surgical procedure without contamination of the sterile field.
It is also necessary that the patient support system be constructed to provide optimum access to the surgical field by the surgery team. Some procedures require positioning of portions of the patient's body in different ways at different times during the procedure. Some procedures, for example, spinal surgery, involve access through more than one surgical site or field. Since all of these fields may not be in the same plane or anatomical location, the patient support surfaces should be adjustable and capable of providing support in different planes for different parts of the patient's body as well as different positions or alignments for a given part of the body. Preferably, the support surface should be adjustable to provide support in separate planes and in different alignments for the head and upper trunk portion of the patient's body, the lower trunk and pelvic portion of the body as well as each of the limbs independently.
Certain types of surgery, such as orthopedic surgery, may require that the patient or a part of the patient be repositioned during the procedure while in some cases maintaining the sterile field. Where surgery is directed toward motion preservation procedures, such as by installation of artificial joints, dynamic stabilization systems, spinal ligaments and total disc prostheses, for example, the surgeon must be able to manipulate certain joints while supporting selected portions of the patient's body during surgery in order to facilitate the procedure. It is also desirable to be able to test the range of motion of the surgically repaired or stabilized joint and to observe the gliding movement of the reconstructed articulating prosthetic surfaces or the tension and flexibility of artificial ligaments, spacers and other types of dynamic stabilizers before the wound is closed. Such manipulation can be used, for example, to verify the correct positioning and function of an implanted prosthetic disc, spinal dynamic longitudinal connecting member, interspinous spacer or joint replacement during a surgical procedure. Where manipulation discloses binding, sub-optimal position or even crushing of the adjacent vertebrae, for example, as may occur with osteoporosis, the prosthesis can be removed and the adjacent vertebrae fused while the patient remains anesthetized. Injury which might otherwise have resulted from a “trial” use of the implant post-operatively will be avoided, along with the need for a second round of anesthesia and surgery to remove the implant or prosthesis and perform the revision, fusion or corrective surgery.
There is also a need for a patient support surface that can be articulated and angulated so that the patient can be moved when prone, for example, into an upwardly angled position or when supine into a downwardly angled position and whereby intra-operative bending (flexion and extension) of at least a portion of the spinal column can be achieved. The patient support surface must also be capable of easy, selective adjustment without necessitating removal and repositioning of the patient or causing substantial interruption of a surgical procedure.
For certain types of surgical procedures, for example spinal surgeries, it may be desirable to position the patient for sequential procedures done anteriorly, posteriorly and laterally. The patient support surface should be capable of providing correct positioning of the patient and optimum accessibility for the surgeon, as well as imaging equipment during such sequential procedures, when the patient is positioned prone, supine and lateral.
Articulated robotic arms are increasingly employed to perform surgical techniques. These units are generally designed to move short distances and to perform very precise work. Reliance on the patient support structure to perform any necessary gross movement of the patient can be beneficial, especially if the movements are synchronized or coordinated. Such units require a surgical support surface capable of smoothly performing the multi-directional movements which would otherwise be performed by trained medical personnel. There is thus a need in this application as well for integration between the robotics technology and the patient positioning technology.
While conventional operating tables generally include structure that permits tilting or rotation of a patient support surface about a longitudinal axis, previous surgical support devices have attempted to address the need for access by providing a cantilevered patient support surface on one end. However, existing cantilevered patient support structures are unsatisfactory, incorporating either a massive base to counterbalance the extended support member or a large overhead frame structure to provide support from above. The enlarged base members associated with such cantilever designs are problematic in that they can and do obstruct the movement of C-arm and O-arm mobile fluoroscopic imaging devices and other equipment. Surgical tables with overhead frame structures are bulky and may require the use of dedicated operating rooms, since in some cases they cannot be moved easily out of the way. Neither of these designs is easily portable or storable.
Articulated operating tables that employ cantilevered support surfaces capable of upward and downward angulation require structure to compensate for variations in the spatial relation of the inboard ends of the supports as they are raised and lowered to an angled position either above or below a horizontal plane. As the inboard ends of the supports are raised or lowered, they form a triangle, with the horizontal plane of the table forming the base of the triangle. Unless the base is commensurately shortened or the frame or patient support structure is elongated, a gap will develop between the inboard ends of the supports.
Such up and down angulation of the patient supports also causes a corresponding flexion or extension, respectively, of the lumbar spine of a supine or prone patient positioned on the supports. Raising the inboard ends of the patient supports generally causes flexion of the lumbar spine of a prone patient with decreased lordosis and a coupled or corresponding posterior rotation of the pelvis around the hips. When the top of the pelvis rotates in a posterior direction, it pulls the lumbar spine and wants to move or translate the thoracic spine in a caudad direction, toward the patient's feet. If the patient's trunk, entire upper body and head and neck are not free to translate or move along the support surface in a corresponding caudad direction in association with the posterior pelvic rotation, excessive traction along the entire spine can occur, but especially in the lumbar region. Conversely, lowering the inboard ends of the patient supports with downward angulation causes extension of the lumbar spine of a prone patient with increased lordosis and coupled anterior pelvic rotation around the hips. When the top of the pelvis rotates in an anterior direction, it pushes and wants to translate the thoracic spine in a cephalad direction, toward the patient's head. If the patient's trunk and upper body are not free to translate or move along the longitudinal axis of the support surface in a corresponding cephalad direction during lumbar extension with anterior pelvic rotation, unwanted compression of the spine can result, especially in the lumbar region.
Thus, there remains a need for a patient support system that provides easy access for personnel and equipment, that can be positioned and repositioned easily and quickly in multiple planes without the use of massive counterbalancing support structure, and that does not require use of a dedicated operating room. There is also a need for such a system that permits upward and downward angulation of the inboard ends of the supports, either alone or in combination with rotation or roll about the longitudinal axis, all while maintaining the ends in a preselected spatial relation, and at the same time providing for coordinated translation of the patient's upper body in a corresponding caudad or cephalad direction to thereby avoid excessive compression or traction on the spine.